Set BAZELISK_USER_AGENT env variable. (#1191)
Set BAZELISK_USER_AGENT env variable. (#1191)

CI should have its own user agent value in order to distinguish itself from "regular" Bazelisk users in the download statistics.

This commit won't have any effect before we deploy Bazelisk v1.10.0 or later to all CI workers.
bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration